Is it possible to decrypt SHA1
Is it possible to decrypt(retain the actual string) the password which is saved in db using SHA1 algorithm.
Example:If password is "password" and it is stored in db as "sha1$4fb4c$2bc693f8a86e2d87f757c382a32e3d50fc945b24",is any chance to retain the same "password"(string) from "sha1$4fb4c$2bc693f8a86e2d87f757c382a32e3d50fc945b24"
Answer
SHA1 is a cryptographic hash function, so the intention of the design was to avoid what you are trying to do.
However, breaking a SHA1 hash is technically possible. You can do so by just trying to guess what was hashed. This brute-force approach is of course not efficient, but that's pretty much the only way.
So to answer your question: yes, it is possible, but you need significant computing power. Some researchers estimate that it costs $70k - $120k.
As far as we can tell today, there is also no other way but to guess the hashed input. This is because operations such as mod eliminate information from your input. Suppose you calculate mod 5 and you get 0. What was the input? Was it 0, 5 or 500? You see, you can't really 'go back' in this case.